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Diffstat (limited to 'sysdeps/aarch64/strchr.S')
| -rw-r--r-- | sysdeps/aarch64/strchr.S | 139 |
1 files changed, 0 insertions, 139 deletions
diff --git a/sysdeps/aarch64/strchr.S b/sysdeps/aarch64/strchr.S deleted file mode 100644 index c5bc79a8c3..0000000000 --- a/sysdeps/aarch64/strchr.S +++ /dev/null @@ -1,139 +0,0 @@ -/* strchr - find a character in a string - - Copyright (C) 2014-2017 Free Software Foundation, Inc. - - This file is part of the GNU C Library. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library. If not, see - <http://www.gnu.org/licenses/>. */ - -#include <sysdep.h> - -/* Assumptions: - * - * ARMv8-a, AArch64 - */ - -/* Arguments and results. */ -#define srcin x0 -#define chrin w1 - -#define result x0 - -#define src x2 -#define tmp1 x3 -#define wtmp2 w4 -#define tmp3 x5 - -#define vrepchr v0 -#define vdata1 v1 -#define vdata2 v2 -#define vhas_nul1 v3 -#define vhas_nul2 v4 -#define vhas_chr1 v5 -#define vhas_chr2 v6 -#define vrepmask_0 v7 -#define vrepmask_c v16 -#define vend1 v17 -#define vend2 v18 - - /* Core algorithm. - For each 32-byte hunk we calculate a 64-bit syndrome value, with - two bits per byte (LSB is always in bits 0 and 1, for both big - and little-endian systems). Bit 0 is set iff the relevant byte - matched the requested character. Bit 1 is set iff the - relevant byte matched the NUL end of string (we trigger off bit0 - for the special case of looking for NUL). Since the bits - in the syndrome reflect exactly the order in which things occur - in the original string a count_trailing_zeros() operation will - identify exactly which byte is causing the termination, and why. */ - -/* Locals and temporaries. */ - -ENTRY (strchr) - DELOUSE (0) - mov wtmp2, #0x0401 - movk wtmp2, #0x4010, lsl #16 - dup vrepchr.16b, chrin - bic src, srcin, #31 - dup vrepmask_c.4s, wtmp2 - ands tmp1, srcin, #31 - add vrepmask_0.4s, vrepmask_c.4s, vrepmask_c.4s // lsl #1 - b.eq L(loop) - - /* Input string is not 32-byte aligned. Rather than forcing - the padding bytes to a safe value, we calculate the syndrome - for all the bytes, but then mask off those bits of the - syndrome that are related to the padding. */ - ld1 {vdata1.16b, vdata2.16b}, [src], #32 - neg tmp1, tmp1 - cmeq vhas_nul1.16b, vdata1.16b, #0 - cmeq vhas_chr1.16b, vdata1.16b, vrepchr.16b - cmeq vhas_nul2.16b, vdata2.16b, #0 - cmeq vhas_chr2.16b, vdata2.16b, vrepchr.16b - and vhas_nul1.16b, vhas_nul1.16b, vrepmask_0.16b - and vhas_nul2.16b, vhas_nul2.16b, vrepmask_0.16b - and vhas_chr1.16b, vhas_chr1.16b, vrepmask_c.16b - and vhas_chr2.16b, vhas_chr2.16b, vrepmask_c.16b - orr vend1.16b, vhas_nul1.16b, vhas_chr1.16b - orr vend2.16b, vhas_nul2.16b, vhas_chr2.16b - lsl tmp1, tmp1, #1 - addp vend1.16b, vend1.16b, vend2.16b // 256->128 - mov tmp3, #~0 - addp vend1.16b, vend1.16b, vend2.16b // 128->64 - lsr tmp1, tmp3, tmp1 - - mov tmp3, vend1.2d[0] - bic tmp1, tmp3, tmp1 // Mask padding bits. - cbnz tmp1, L(tail) - -L(loop): - ld1 {vdata1.16b, vdata2.16b}, [src], #32 - cmeq vhas_nul1.16b, vdata1.16b, #0 - cmeq vhas_chr1.16b, vdata1.16b, vrepchr.16b - cmeq vhas_nul2.16b, vdata2.16b, #0 - cmeq vhas_chr2.16b, vdata2.16b, vrepchr.16b - /* Use a fast check for the termination condition. */ - orr vend1.16b, vhas_nul1.16b, vhas_chr1.16b - orr vend2.16b, vhas_nul2.16b, vhas_chr2.16b - orr vend1.16b, vend1.16b, vend2.16b - addp vend1.2d, vend1.2d, vend1.2d - mov tmp1, vend1.2d[0] - cbz tmp1, L(loop) - - /* Termination condition found. Now need to establish exactly why - we terminated. */ - and vhas_nul1.16b, vhas_nul1.16b, vrepmask_0.16b - and vhas_nul2.16b, vhas_nul2.16b, vrepmask_0.16b - and vhas_chr1.16b, vhas_chr1.16b, vrepmask_c.16b - and vhas_chr2.16b, vhas_chr2.16b, vrepmask_c.16b - orr vend1.16b, vhas_nul1.16b, vhas_chr1.16b - orr vend2.16b, vhas_nul2.16b, vhas_chr2.16b - addp vend1.16b, vend1.16b, vend2.16b // 256->128 - addp vend1.16b, vend1.16b, vend2.16b // 128->64 - - mov tmp1, vend1.2d[0] -L(tail): - sub src, src, #32 - rbit tmp1, tmp1 - clz tmp1, tmp1 - /* Tmp1 is even if the target charager was found first. Otherwise - we've found the end of string and we weren't looking for NUL. */ - tst tmp1, #1 - add result, src, tmp1, lsr #1 - csel result, result, xzr, eq - ret -END (strchr) -libc_hidden_builtin_def (strchr) -weak_alias (strchr, index) |